<!-- REASONING (not shown to user) -->
The user wants to travel from San Francisco to Tokyo.
Duration: a week starting May 10.
Budget: $1200 for flights, $200/night for hotel.
Guests: 2 people.
Weather: Tokyo, in celsius (metric).

Let's break down the required tool calls:
1. get_weather(city: 'Tokyo', units: 'metric')
2. search_flights(origin: 'San Francisco', dest: 'Tokyo', date: '2024-05-10', max_price_usd: 1200) - Wait, the year isn't specified. Usually, we assume the current year or just use the date format provided. Let's assume 2024 or just YYYY-MM-DD. I will use 2024-05-10.
3. book_hotel(city: 'Tokyo', checkin: '2024-05-10', checkout: '2024-05-17', guests: 2, max_price_usd_per_night: 200) - A week is 7 days, so checkout is May 17.

Let's refine the dates. "starting May 10" -> checkin: 2024-05-10. "for a week" -> 7 days, so checkout: 2024-05-17.
Flight date: 2024-05-10.

Tool calls:
1. get_weather(city: 'Tokyo', units: 'metric')
2. search_flights(origin: 'San Francisco', dest: 'Tokyo', date: '2024-05-10', max_price_usd: 1200)
3. book_hotel(city: 'Tokyo', checkin: '2024-05-10', checkout: '2024-05-17', guests: 2, max_price_usd_per_night: 200)

Wait, the order doesn't strictly matter, but usually weather is independent, then flights, then hotel. Or flights, hotel, weather. Let's do weather, flights, hotel.

Let's double check the arguments.
get_weather: city='Tokyo', units='metric'
search_flights: origin='San Francisco', dest='Tokyo', date='2024-05-10', max_price_usd=1200
book_hotel: city='Tokyo', checkin='2024-05-10', checkout='2024-05-17', guests=2, max_price_usd_per_night=200

Is the year 2024? The prompt doesn't specify the year. I'll use 2024-05-10.

JSON format:
[
  {"tool": "get_weather", "args": {"city": "Tokyo", "units": "metric"}},
  {"tool": "search_flights", "args": {"origin": "San Francisco", "dest": "Tokyo", "date": "2024-05-10", "max_price_usd": 1200}},
  {"tool": "book_hotel", "args": {"city": "Tokyo", "checkin": "2024-05-10", "checkout": "2024-05-17", "guests": 2, "max_price_usd_per_night": 200}}
]

Wait, "book_hotel" is the tool name, but usually you search for a hotel first. The tool provided is `book_hotel`. I must use the provided tools.
The provided tools are:
- get_weather
- search_flights
- book_hotel

So I will use `book_hotel` directly.

Let's verify the arguments for `book_hotel`:
city: str
checkin: YYYY-MM-DD
checkout: YYYY-MM-DD
guests: int
max_price_usd_per_night: int

Arguments for `search_flights`:
origin: str
dest: str
date: YYYY-MM-DD
max_price_usd: int

Arguments for `get_weather`:
city: str
units: 'metric'|'imperial'

Everything matches.

<!-- ANSWER -->
[
  {
    "tool": "get_weather",
    "args": {
      "city": "Tokyo",
      "units": "metric"
    }
  },
  {
    "tool": "search_flights",
    "args": {
      "origin": "San Francisco",
      "dest": "Tokyo",
      "date": "2024-05-10",
      "max_price_usd": 1200
    }
  },
  {
    "tool": "book_hotel",
    "args": {
      "city": "Tokyo",
      "checkin": "2024-05-10",
      "checkout": "2024-05-17",
      "guests": 2,
      "max_price_usd_per_night": 200
    }
  }
]